Photochemical characterization of water samples from Minnesota and Vermont sites with malformed frogs: potential influence of photosensitization by singlet molecular oxygen (1O2) and free radicals on aquatic toxicity

2003 ◽  
Vol 65 (3) ◽  
pp. 229-241 ◽  
Author(s):  
P Bilski ◽  
J.G Burkhart ◽  
C.F Chignell
1992 ◽  
Vol 5 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Steen Steenken ◽  
Alfred R. Sundquist ◽  
Slobodan V. Jovanovic ◽  
Rowena Crockett ◽  
Helmut Sies

2015 ◽  
Vol 70 (10) ◽  
pp. 719-725 ◽  
Author(s):  
Cristian Villa-Pérez ◽  
Isabel C. Ortega ◽  
Angélica M. Payán-Aristizábal ◽  
Gustavo Echeverría ◽  
Gloria C. Valencia-Uribe ◽  
...  

AbstractA new complex of Hg(II) with 6-methoxyquinoline (C10H9NO-6MQ) has been synthesized and characterized. The structure of the complex Hg(6MQ)Cl2 was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/c with a = 3.9139(3), b = 26.3400(2), c = 10.9090(9) Å, β = 89.833(6)°, V = 1124.6(1) Å3 and Z = 4 molecules per unit cell. The coordination geometry of the mercury(II) center can be described as a distorted square pyramid formed by one nitrogen atom of the 6MQ and four chlorine atoms. Fourier transform infrared, Raman and UV/Vis spectroscopic studies have been carried out to characterize the compound, using theoretical calculations for the assignment of the experimentally observed bands. The thermal behavior was investigated by thermogravimetric analysis. The quantum yield of singlet molecular oxygen production ΦΔ was measured with steady-state methods in ethanol, using 9,10-dimethylanthracene (DMA) as actinometer and Bengal rose as reference photosensitizer. The resultant singlet molecular oxygen was detected indirectly by photooxidation reactions of DMA. The luminescence properties have also been studied.


2010 ◽  
Vol 49 ◽  
pp. S99-S100 ◽  
Author(s):  
Marilene Silva Oliveira ◽  
Divinomar Severino ◽  
Fernanda Manso Prado ◽  
Maiara Oliveira Salles ◽  
Mauricio César Bof de Oliveira ◽  
...  

Author(s):  
Ahmad Z Al-Herrawy ◽  
Mohamed A Marouf ◽  
Mahmoud A. Gad

Genus Acanthamoeba causes 3 clinical syndromes amebic keratitis, granulomatous amebic encephalitis and disseminated granulomatous amebic disease (eg, sinus, skin and pulmonary infections). A total of 144 tap water samples were collected from Giza governorate, Egypt. Samples were processed for detection of Acanthamoeba species using non-nutrient agar (NNA) and were incubated at 30oC. The isolates of Acanthamoeba were identified to species level based on the morphologic criteria. Molecular characterization of the Acanthamoeba isolates to genus level was performed by using PCR. The obtained results showed that the highest occurrence percentage of Acanthamoeba species in water samples was observed in summer season (38.9%), then it decreased to be 30.6% in spring and 25% in each of autumn and winter. PCR analysis showed that 100% of 43 Acanthamoeba morphologically positive samples were positive by genus specific primer. In the present study eight species of Acanthamoeba can be morphologically recognized namely Acanthamoeba triangularis, Acanthamoeba echinulata, Acanthamoeba astronyxis, Acanthamoeba comandoni, Acanthamoeba griffini, Acanthamoeba culbertsoni, Acanthamoeba quina and Acanthamoeba lenticulata. In conclusion, the most common Acanthamoeba species in tap water was Acanthamoeba comandoni


2006 ◽  
Vol 985 ◽  
Author(s):  
Brian D Marshall ◽  
Thomas A. Oliver ◽  
Zell E. Peterman

AbstractWater samples (referred to as puddle water samples) were collected from the surfaces of a conveyor belt and plastic sheeting in the unventilated portion of the Enhanced Characterization of the Repository Block (ECRB) Cross Drift in 2003 and 2005 at Yucca Mountain, Nevada. The chemistry of these puddle water samples is very different than that of pore water samples from borehole cores in the same region of the Cross Drift or than seepage water samples collected from the Exploratory Studies Facility tunnel in 2005. The origin of the puddle water is condensation on surfaces of introduced materials and its chemistry is dominated by components of the introduced materials. Large CO2 concentrations may be indicative of localized chemical conditions induced by biologic activity.


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